391266068857 has 2 divisors, whose sum is σ = 391266068858. Its totient is φ = 391266068856.

The previous prime is 391266068849. The next prime is 391266068917. The reversal of 391266068857 is 758860662193.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 236379743721 + 154886325136 = 486189^2 + 393556^2 .

It is a cyclic number.

It is not a de Polignac number, because 391266068857 - 2³ = 391266068849 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 391266068795 and 391266068804.

It is not a weakly prime, because it can be changed into another prime (391266068827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 195633034428 + 195633034429.

It is an arithmetic number, because the mean of its divisors is an integer number (195633034429).

Almost surely, 2^391266068857 is an apocalyptic number.

It is an amenable number.

391266068857 is a deficient number, since it is larger than the sum of its proper divisors (1).

391266068857 is an equidigital number, since it uses as much as digits as its factorization.

391266068857 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 26127360, while the sum is 61.

The spelling of 391266068857 in words is "three hundred ninety-one billion, two hundred sixty-six million, sixty-eight thousand, eight hundred fifty-seven".